Blackberry--Navaho Cultivar

ABSTRACT

Description and specifications of a new and distinct blackberry variety which originated from seed produced by a hand-pollinated cross of Arkansas Selection 583 (non-patented) and Arkansas Selection 631 (non-patented) is provided. This new blackberry variety can be distinguished by its thornless canes with erect growth habit, its late ripening, and its excellent fruit flavor.

SUMMARY OF THE INVENTION

The new and distinct variety of blackberry originated from ahand-pollinated cross of Arkansas Selection 583 (non-patented)×ArkansasSelection 631 (non-patented) made in 1977 at the Arkansas AgriculturalExperiment Station Fruit Substation at Clarksville, Ark. The seedsresulting from this controlled hybridization were germinated in agreenhouse in the spring of 1978 and planted in a field on the ArkansasAgricultural Experiment Station in Clarksville, Ark. The seedlingsfruited during the summer of 1980 and one, designated Ark. 1172, wasselected for its thornless canes, erect growth habit, and high fruitquality.

During 1981, the original plant selection was propagated asexually fromroot cuttings and a test row of 20 plants was established. Subsequently,larger test plantings have been established with asexually multipledplants at four additional locations in Arkansas and on state experimentstations in Illinois, Louisiana, Florida, Texas, North Carolina andMississippi.

The new variety has been asexually multiplied annually since 1981 by theuse of root cuttings and by rooting softwood cuttings. It forms newplants from adventitious buds on most root cuttings, but is bestpropagated by rooting softwood cuttings. During all asexualmultiplication, the characteristics of the original plant have beenmaintained and no aberrant phenotypes have appeared.

Test plantings over a wide geographic area have shown this new varietyto be adapted to differing soil and climatic conditions. It hasperformed well in tests in the Southeast U.S. but is not cold hardy innorthern states.

Plants of the new variety are moderately vigorous and row establishmentfollowing planting is more rapid than with other thornless varieties.Both primocanes and floricanes are erect in growth habit and the newvariety is the first truly erect thornless variety to be developed. Theplants are genetically thornless, having the recessive genes forthornlessness derived from Merton Thornless. Plants and fruit aremoderately tolerant to anthracnose (Elsinoe veneta (Burkh.) Jenkins),and plants are immune to orange rust (Gymnoconia peckiana (Howe) Trott).

Fruit of the new variety ripens late, about 15 days after the Cheyennevariety, and 7 days after the Shawneee variety, but about 5 days earlierthan Dirksen Thornless, a standard thornless cultivar. Average ripeningdate is June 25 in central Arkansas. The harvest period is longer thanmost other erect varieties; it produces well for a full month. Fruityields are comparable with the Cheyenne variety but are less than theShawnee variety. Late spring budbreak avoids spring frosts and the newvariety is consistent in yield from year to year.

The fruit is short conic in shape, bright glossy black in color andmedium in size (ca. 5.1 g). The fruit is firm at maturity, consistentlyrating more firm than fruit of the Cheyenne and Shawnee varieties.

The fresh fruit has better flavor than any extant variety of thornlessblackberry and is rated superior to the thorny varieties Cheyenne andShawnee. The soluble solids content averages 11.2%, higher than mostblackberry varieties. Seed size is smaller than other thornlessvarieties now in existence.

Fruit clusters are medium-large, cymose, and are borne on the peripheryof the plant canopy, providing easy access to harvest. Flower fertilityis high and clusters are well filled.

The new variety has been named the Navaho cultivar.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show typical specimens of the fruit andleaf of the new variety in color as nearly true as it is reasonablypossible to make in a color illustration of this character.

DETAILED DESCRIPTION OF THE NEW VARIETY

The following is a detailed description of the pomologicalcharacteristics of the subject blackberry. Color terminology is inaccordance with that of the Royal Horticultural Society Colour Chartpublished in 1966 by The Royal Horticultural Society of London, England.

Where dimensions, sizes, colors and other characteristics are given, itis to be understood that such characteristics are approximations ofaverages set forth as accurately as practicable.

The descriptions reported herein are from specimens group atClarksville, Ark. unless otherwise noted.

Plant:

Size.--Medium, erect.

Growth.--Vigorous; prolific suckering from crowns, sparse suckering fromroots.

Productivity.--High and for duration of one month; consistent from yearto year.

Cold hardiness.--Medium, similar to Cheyenne.

Canes.--Erect, thornless. Cane diameter: Base 2.1 cm, midpoint 1.4 cm,terminal 0.3 cm. Internode length: Base 5.0 cm, midpoint 8.4 cm,terminal 3.4 cm. Floricane color: Base Brown Group (200B), midpointYellow-Green Group (152B), terminal Brown Group (200B). Primocane color:Base Greyed-Orange Group (175A), terminal Yellow-Green Group (146C) Dateof primocane emergence April 2.

Disease resistance.--Moderate for anthracnose; immune to orange rust.

Foliage:

Leaves.--Large. Mature leaf diameter 7 cm; length 7.6 cm. Color:Floricane base Yellow-Green Group (147A), floricane terminalYellow-Green Group (147B); Primocane base Yellow-Green Group (137A),primocane terminal Yellow-Green Group (137B).

Flowers:

Date of first bloom.--April 11.

Date of last bloom.--May 22.

Blossom color.--Yellow-White Group (158D) with occasional pink atborder.

Reproductive organs.--Stamens -- erect, numerous. Pistils -- numerous.Pollen -- normal and abundant.

Number flowers per cluster.--6.4.

Number petals per flower.--6.0.

Fruit:

Maturity.--Late, 15 days after Cheyenne. Average ripe date June 25,average period of maturity June 25-July 25.

Size.--Medium, average 5.1 g, uniform. Diameter primary fruit equator2.3 cm, base pole 1.6 cm, terminal pole 1.2 cm; secondary fruit equator2.0 cm, base pole 1.4 cm terminal pole 1.0 cm. Length: primary fruit 2.5cm, secondary fruit 2.3 cm, tertiary fruit 2.2 cm.

Shape.--Short, conic, uniform.

Color.--Glossy black (Black Group 202A).

Skin.--Medium tender.

Drupelet size.--Medium (0.6 cm).

Seed size.--Medium large, 3.9 mg.

Firmness.--Good, superior to Cheyenne.

Flavor.--Very good, sweet.

Soluble solids.--11.2%.

pH.--3.01.

Total acids.--1.137%.

Processed quality.--Very good, superior to Cheyenne and Shawnee.

Uses.--Fresh and processed, jellies, jams.

The variety: The most distinctive features of the variety are itsthornless canes with erect growth habit, late ripening, and outstandingfruit flavor.

I claim:
 1. A new and distinct variety of blackberry, substantially asillustrated and described, characterized by its thornless, erect growingcanes, late ripening, and excellent fruit flavor.